Try a larger or different type of bag and put a waterproof sheet on the bed. I'm not sure if your ileostomy is temporary or permanent, but this sort of thing is not that uncommon for the first few months after surgery. It's partly because of the bowels not having settled into their new function yet (thus leading to more gas/output) and partly because of not having found the optimal setup. I used to wake up every morning with my bag resembling a zeppelin, although the only time I had a major disaster in bed was in the middle of the night. Took about
an hour to strip the sheets, rinse them down etc.
It does get better. It takes up to a year for the bowels to adjust, but once they do you should be able to go through the night without needing to get up to empty the bag. As for the pouching setup, not at all bags are created equal. A convex wafer should be used if your stoma is too short (a more common problem with temporary loop ileostomies). Otherwise it's largely a matter of experimenting with different brands of bags and accessories. I use a 1-piece Coloplast Sensura, change it every 2-3 days, and virtually never have leaks any more. The Coloplast bags aren't perfect, but they stick extremely well and that's by far and away by most important criteria, to be honest. I use them in conjunction with Eakin seals.
Dx Crohn's in summer of 2000. (Yay )
Tried and failed: 5-ASAs, Azathioprine, 6MP, Remicade, Methotrexate, Humira.
Diet didn't make any difference either.
Had surgery 2/13 - subtotal colectomy with end ileostomy. Currently on no meds and in remission. Also prone to depression and anxiety. Ask me anything >_>